This invention relates in general to body and frame assemblies for vehicles. In particular, this invention relates to an improved structure for a structural component for use in such a vehicle body and frame assembly.
Many land vehicles in common use, such as automobiles, vans, and trucks, include a body and frame assembly that is supported upon a plurality of ground-engaging wheels by a resilient suspension system. The structures of known body and frame assemblies can be divided into two general categories, namely, separate and unitized. In a typical separate body and frame assembly, the structural components of the body portion and the frame portion of the vehicle are separate and independent from one another. When assembled, the frame portion of the assembly is resiliently supported upon the vehicle wheels by the suspension system and serves as a platform upon which the body portion of the assembly and other components of the vehicle can be mounted. Separate body and frame assemblies of this general type are found in most older vehicles, but remain in common use today for many relatively large or specialized use modern vehicles, such as large vans, sport utility vehicles, and trucks. In a typical unitized body and frame assembly, the structural components of the body portion and the frame portion are combined into an integral unit that is resiliently supported upon the vehicle wheels by the suspension system. Unitized body and frame assemblies of this general type are found in many relatively small modern vehicles, such as automobiles and minivans.
As mentioned above, each of these body and frame assemblies is composed of a plurality of individual structural components that are secured together. In the past, each of these structural components has been formed from a single piece of metallic material, and all of the structural components have been formed from the same metallic material. Steel has traditionally been the preferred metallic material for manufacturing all of such structural components because of its relatively high strength, relatively low cost, and ease of manufacture. Also, when all of the structural components are formed from the same or similar metallic materials, it is relatively easy to secure them together using conventional welding techniques, which usually involve the application of heat to localized areas of two metallic members so as to cause a coalescence of the two metallic members.
More recently, however, it has been found desirable to form some of the structural components from a first metallic material and others of the structural components from a second metallic material. For example, in a ladder frame type of vehicle frame assembly, the side rails can be formed from steel, while the cross members can be formed from aluminum or magnesium. The use of such alternative metallic materials to form some of the structural components is desirable because it can significantly reduce the overall weight of the vehicle body and frame assembly. Unfortunately, conventional welding techniques are not well suited for securing together components that are formed from dissimilar metallic materials. Magnetic pulse welding is a process that can be used to secure together the structural components that are formed from dissimilar metallic materials. Although magnetic pulse welding is an effective method for securing such structural components together in a manufacturing facility, it would be relatively difficult to perform such an operation elsewhere, such as in a small repair shop if a portion of the vehicle frame assembly was damaged and required replacement. Thus, it would be desirable to provide an improved structure for a structural component, such as for use in a vehicle body and frame assembly, that addresses both concerns of weight reduction and ease of securement.